diff --git a/README.md b/README.md
index bfcc67d..0be9b61 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,7 @@ unchanged.
 | `PLANE_API_KEY` | stdio | API key |
 | `PLANE_WORKSPACE_SLUG` | stdio | Target workspace |
 | `PLANE_BASE_URL` | optional | Plane API URL (default `https://api.plane.so`) |
+| `PLANE_SSL_VERIFY` | optional | TLS verification for `PLANE_BASE_URL` / `PLANE_INTERNAL_BASE_URL` (default: verify normally). `false`/`0`/`no` disables verification entirely — a warning is logged on every use, since this removes protection against a man-in-the-middle; only use it for a self-hosted instance you control. A path to an existing file is treated as a CA bundle. |
 
 The remote transports carry credentials in the connection — the OAuth flow or the
 PAT headers — and need none of these.
diff --git a/plane_mcp/client.py b/plane_mcp/client.py
index dd8c6b6..ea33db6 100644
--- a/plane_mcp/client.py
+++ b/plane_mcp/client.py
@@ -18,6 +18,44 @@ class PlaneClientContext(NamedTuple):
     workspace_slug: str
 
 
+def _resolve_ssl_verify(base_url: str) -> bool | str:
+    """
+    Resolve TLS verification mode from PLANE_SSL_VERIFY.
+
+    - Unset (default): verify=True, normal certificate verification.
+    - "false"/"0"/"no" (case-insensitive): verify=False, disable verification
+      entirely. Logs a warning on every call since this drops protection
+      against a man-in-the-middle.
+    - Any other value that names an existing file path: treated as a CA
+      bundle and passed through verbatim.
+    - Anything else: verify=True (fail safe rather than silently misparse).
+    """
+    raw = os.environ.get("PLANE_SSL_VERIFY")
+    if not raw:
+        return True
+
+    if raw.strip().lower() in ("false", "0", "no"):
+        logger.warning(
+            "TLS verification is DISABLED for %s (PLANE_SSL_VERIFY=%s). "
+            "The connection has no protection against a man-in-the-middle; "
+            "requests, responses, and the API key are exposed to anyone "
+            "positioned on the network path.",
+            base_url,
+            raw,
+        )
+        return False
+
+    if os.path.exists(raw):
+        return raw
+
+    logger.warning(
+        "PLANE_SSL_VERIFY=%s is neither false/0/no nor an existing file path; "
+        "falling back to verify=True.",
+        raw,
+    )
+    return True
+
+
 def get_plane_client_context() -> PlaneClientContext:
     """
     Initialize and return a PlaneClient instance with workspace context.
@@ -30,6 +68,9 @@ def get_plane_client_context() -> PlaneClientContext:
     Environment variables:
     - PLANE_INTERNAL_BASE_URL: Internal URL for Plane API (preferred for server-to-server calls)
     - PLANE_BASE_URL: Base URL for Plane API (fallback, default: https://api.plane.so)
+    - PLANE_SSL_VERIFY: TLS verification mode. Unset/default = verify normally.
+      "false"/"0"/"no" = disable verification entirely (logs a warning on every
+      use). A path to an existing file = treated as a CA bundle.
 
     Returns:
         PlaneClientContext containing configured PlaneClient instance and workspace slug
@@ -57,15 +98,19 @@ def get_plane_client_context() -> PlaneClientContext:
         else:
             access_token = token
 
+    verify = _resolve_ssl_verify(base_url)
+
     if access_token:
         client = PlaneClient(
             base_url=base_url,
             access_token=access_token,
+            verify=verify,
         )
     else:
         client = PlaneClient(
             base_url=base_url,
             api_key=api_key,
+            verify=verify,
         )
 
     return PlaneClientContext(
diff --git a/tests/test_client_ssl_verify.py b/tests/test_client_ssl_verify.py
new file mode 100644
index 0000000..b7d58ef
--- /dev/null
+++ b/tests/test_client_ssl_verify.py
@@ -0,0 +1,38 @@
+"""Unit tests for PLANE_SSL_VERIFY parsing in plane_mcp.client._resolve_ssl_verify.
+
+Pure function, no network and no live Plane instance required.
+"""
+
+import pytest
+
+from plane_mcp.client import _resolve_ssl_verify
+
+
+def test_default_is_true_when_unset(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("PLANE_SSL_VERIFY", raising=False)
+    assert _resolve_ssl_verify("https://plane.example.com") is True
+
+
+@pytest.mark.parametrize("raw", ["false", "False", "FALSE", "0", "no", "No"])
+def test_falsy_values_disable_verification(monkeypatch: pytest.MonkeyPatch, raw: str) -> None:
+    monkeypatch.setenv("PLANE_SSL_VERIFY", raw)
+    assert _resolve_ssl_verify("https://plane.example.com") is False
+
+
+def test_existing_file_path_is_passed_through_verbatim(
+    monkeypatch: pytest.MonkeyPatch, tmp_path
+) -> None:
+    ca_bundle = tmp_path / "internal-ca.pem"
+    ca_bundle.write_text("fake cert content")
+    monkeypatch.setenv("PLANE_SSL_VERIFY", str(ca_bundle))
+    assert _resolve_ssl_verify("https://plane.example.com") == str(ca_bundle)
+
+
+def test_nonexistent_path_falls_back_to_true(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("PLANE_SSL_VERIFY", "/no/such/path/ca.pem")
+    assert _resolve_ssl_verify("https://plane.example.com") is True
+
+
+def test_empty_string_is_treated_as_unset(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("PLANE_SSL_VERIFY", "")
+    assert _resolve_ssl_verify("https://plane.example.com") is True